Occupant-Sensing Imaging System

Abstract

A sensing system for an automotive vehicle comprises at least one imager element and at least one illuminating device to be arranged within an autom-otive vehicle for sensing the presence of an object in a sensing area associated to said vehicle. According to the invention the illuminating device comprises at least one light source for generating a light beam and light beam shaping means for generating an inhomogeneous light distribution in said sensing area, said inhomogeneous light distribution presenting at least one intensity maximum in a specific region of said sensing area.

Description

DETAILED DESCRIPTION WITH RESPECT TO THE FIGURES

The present invention will be more apparent from the following description of several not limiting embodiments with reference to the attached drawings, wherein

FIG. 1: a schematic view of a car interior with an imager system fro the passenger side;

FIG. 2: a schematic front view of an imager system;

FIG. 3: a schematic side view of a single light emitting element with beam shaping optics.

FIG. 1 shows a schematic top view of a car interior 10 equipped with a sensing system 12 for the passenger side. The sensing device 12 comprises e.g. a 3D imaging camera and an illuminating device arranged in a single housing located in the ceiling of the car. The illuminating device is used to provide a time-modulated illumination distribution on a part of the car interior. This illumination is reflected by the interior and a possible occupant, and the reflected light is used as input for a 3D-imaging camera. The 3D-image provided by the camera is used for car-occupant sensing applications.

The illuminating device is formed by an array of several lighting elements 14 formed by a semiconductor optoelectronic light source on a dedicated substrate 16 and an appropriate beam shaping optics 18. The different lighting elements 14 are e.g. arranged in an appropriate array configuration around the optical system 24 of the imager element. The outputs of the lighting elements 14 are individually processed by an optimized combination of refractive and diffractive micro-optics 18 in order to provide the required illumination distribution. The beam shaping optics 18 are optimized such that the total illumination generated from the different light sources 14 corresponds to a predefined illumination distribution in relation to the geometry of the sensing area.

In a preferred embodiment, the light sources are light emitting diodes 20, which are placed inside a cavity 22 with reflecting surfaces of the substrate 16 in order to provide a more directional output. A lens 26 of focal length f is disposed in front of the light emitting diode 20 at a distance d. The lens 20 is provided for shaping the size of the light beam prior to its entry into the diffractive element 28. The light then passes through a diffractive optical element 28, which redirects the light into several partial beams 30, 32, 34 with different intensity ratios and propagating into different directions.

It will be noted, that the use of beam shaping optics 18, which are a combination of refractive 26 and diffractive 28 optics, provides an ease of adaptability of the illumination distribution to different car types. Only the diffraction pattern of the diffractive optical elements 28 has to be adapted, while both the light source 20 as well as the refractive optics 26 do not change.

List of Reference Numerals

• 10 car interior
• 12 sensing device
• 14 lighting elements
• 16 substrate
• 18 beam shaping optics
• 20 light emitting diode
• 22 cavity
• 24 optical system of the imager element
• 26 lens
• 28 diffractive element
• 30, 32, 34 partial beams

Claims

1-14. (canceled)

15. Sensing system for an automotive vehicle, comprising at least one 3D camera and at least one illuminating device to be arranged within an automotive vehicle for sensing the presence of an object in a sensing area associated to said vehicle, said illuminating device comprising at least one light source for generating a light beam and light beam shaping means for generating an inhomogeneous light distribution in said sensing area, said inhomogeneous light distribution presenting at least one intensity maximum in a specific region of said sensing area.

16. Sensing system according to claim 15, wherein said beam shaping means comprises a diffractive optical element arranged in front of said at least one light source, said diffractive optical element being configured for splitting light from said at least one light source into different partial beams with predefined intensity ratios and propagating into predefined directions.

17. Sensing system according to claim 16, wherein said beam shaping means further comprises a refractive optical element arranged between said at least one light source and said diffractive optical element.

18. Sensing system according to claim 15, wherein said illuminating device comprises a plurality of individual light sources arranged in an array configuration.

19. Sensing system according to claim 18, wherein said beam shaping means comprises a plurality of individual optical elements, each individual optical element being associated to one individual light source.

20. Sensing system according to claim 19, wherein said individual optical elements are refractive optical elements arranged in front of the associated light source in such a way, that an optical axis of each refractive optical element is offset with respect to an optical axis of said associated light source.

21. Sensing system according to claim 15, wherein said specific region is located in a furthest part of the sensing area with respect to the 3D camera and/or the illuminating device.

22. Sensing system according to claim 15, wherein said specific region is located in the vicinity of a vehicle dashboard.

23. Sensing system according to claim 15, wherein said specific region is located in the vicinity of a headrest position of the vehicle seat.

24. Sensing system according to claim 15, wherein said 3D camera and said illuminating device are configured to be arranged adjacent to each other in the vehicle.

25. Sensing system according to claim 15, wherein said 3D camera and said illuminating device are configured to be arranged in distant locations in the vehicle.

26. Sensing system according to claim 15, wherein said illuminating device comprises means for adjusting the illumination intensity of said at least one light source.

27. Occupant-sensing system for an automotive vehicle comprising a sensing system including at least one 3D camera and at least one illuminating device to be arranged within an automotive vehicle for sensing the presence of an object in a sensing area associated to said vehicle, said illuminating device comprising at least one light source for generating a light beam and light beam shaping means for generating an inhomogeneous light distribution in said sensing area, said inhomogeneous light distribution presenting at least one intensity maximum in a specific region of said sensing area, wherein said 3D camera and said illuminating device are arranged within a passenger compartment so that the sensing area covers a part of the vehicle interior compartment.

28. Occupant-sensing system according to claim 27, wherein said beam shaping means comprises a diffractive optical element arranged in front of said at least one light source, said diffractive optical element being configured for splitting light from said at least one light source into different partial beams with predefined intensity ratios and propagating into predefined directions.

29. Occupant-sensing system according to claim 28, wherein said beam shaping means further comprises a refractive optical element arranged between said at least one light source and said diffractive optical element.

30. Occupant-sensing system according to claim 27, wherein said illuminating device comprises a plurality of individual light sources arranged in an array configuration and wherein said beam shaping means comprises a plurality of individual optical elements, each individual optical element being associated to one individual light source.

31. Occupant-sensing system according to claim 30, wherein said individual optical elements are refractive optical elements arranged in front of the associated light source in such a way, that an optical axis of each refractive optical element is offset with respect to an optical axis of said associated light source.

32. Obstacle-sensing system for an automotive vehicle comprising a sensing system including at least one 3D camera and at least one illuminating device to be arranged within an automotive vehicle for sensing the presence of an object in a sensing area associated to said vehicle, said illuminating device comprising at least one light source for generating a light beam and light beam shaping means for generating an inhomogeneous light distribution in said sensing area, said inhomogeneous light distribution presenting at least one intensity maximum in a specific region of said sensing area, wherein said 3D camera and said illuminating device are arranged in said vehicle so that the sensing area covers a part of the surroundings of the vehicle.

33. Obstacle-sensing system according to claim 32, wherein said beam shaping means comprises a diffractive optical element arranged in front of said at least one light source, said diffractive optical element being configured for splitting light from said at least one light source into different partial beams with predefined intensity ratios and propagating into predefined directions.

34. Obstacle-sensing system according to claim 33, wherein said beam shaping means farther comprises a refractive optical element arranged between said at least one light source and said diffractive optical element.

35. Obstacle-sensing system according to claim 32, wherein said illuminating device comprises a plurality of individual light sources arranged in an array configuration and wherein said beam shaping means comprises a plurality of individual optical elements, each individual optical element being associated to one individual light source.

36. Obstacle-sensing system according to claim 35, wherein said individual optical elements are refractive optical elements arranged in front of the associated light source in such a way, that an optical axis of each refractive optical element is offset with respect to an optical axis of said associated light source.